242 



Mr M c Glelland, On the Conductivity of Gases 



the lower end of the funnel, and is connected to a gas bag, so 

 that a stream of gas can be sent through the apparatus. 



TO GASBAG 



STORAGE 

 CELLS 



F/?OM G/IS BAG 



Fig. 1- 



A constant flow of gas can thus be obtained from the arc 

 through the tube A, and when the gas bag is properly calibrated 

 the velocity of the stream of gas is known. When a gas other 

 than air is being used a second bag is joined to the upper end of 

 the tube A, so that the gas can be collected after passing through 

 the apparatus and can be used again. 



A terminal B, 7"6 cms. long and '4 cms. diameter, is inserted in 



